What the vulnerability does
01Description
Vite is a frontend tooling framework for javascript. The Vite dev server option `server.fs.deny` can be bypassed on case-insensitive file systems using case-augmented versions of filenames. Notably this affects servers hosted on Windows. This bypass is similar to CVE-2023-34092 -- with surface area reduced to hosts having case-insensitive filesystems. Since `picomatch` defaults to case-sensitive glob matching, but the file server doesn't discriminate; a blacklist bypass is possible. By requesting raw filesystem paths using augmented casing, the matcher derived from `config.server.fs.deny` fails to block access to sensitive files. This issue has been addressed in vite@5.0.12, vite@4.5.2, vite@3.2.8, and vite@2.9.17. Users are advised to upgrade. Users unable to upgrade should restrict access to dev servers.
